Refining mineral oils



Oct. 5, 1943. .5. R. s'TRlcKLAND 2,331,244

0 7 Tree @n man? .Sau/wr Z6 /f 6g f2 l' Patented Oct. 5, 1943 2331244 Y n REFINING `MINERAL onsk .f

Y Barney R.' Strickland, Roselle, .Ni sosiirgnor to j f 7 .Standard Oil Development` Comparini"4 con poration yotDela'wnre i j Apgiieetionenecesierv,1940,'seria1vNj.361062 4'jffisiies.VV (011260-514) Y y,The presentmveimoh renten@ the refining of mineral' oils; The inventions'ls especelly con? cemed with :the removal, segregationand-lrecovery: :of: naturally occurring' acid-ic oxygen` containy ing' compounds: from mineral oils contaim-ng n the same;V The invention-fisk particnlarlyf-y concerned Y gate, andffecoverfthephenolic.typeicompoiinds y' f` andf'naphthenic facids from the; reagentiandatov fully regenerate or revivify thesame. The proc- `withI animprovedfmethod for the removalend n recovery :fof ,-'naturally "ocourringi petroleum f :oil

' .-phe'nolsand'petroleumV oilv timoh-theme.,,4v acids utiv y liningf a', solid` freagent consisting Vrsub,stantielly of 'highly vporous silica,` gel prepared underv certain specific conditions whereby abriticall vquantity pf n presentinvention not vonlyc'i'POvers" these: valubie materials in an: elcient and economical -lnmnnen but alsoproducesi high-,quality treated eoil' product;

Itis known in naphthenic acid-s bywariousokmcthods'since these materials are `relatively valuable and are desir;

able, forV example. was inhibiting @agents ad.

,intermediate ifeed fiproducts. One` method geurnently Iemployed tol Contact thegphenol` and naphthenic acid .containing petroleum oil .with various "aqueous solutions-of alkalillmetal hy- :droxides and the like in order tdform theacorrespending phenomtes Vamo 1 naphthenates.

fsalts A2me.,soluble ln-xandare removedy Withthe spent ,aqueous ,a1,11 ,t.1.i;fmetaflvhvf1r0-xidet Solution-f i y The ,r'respon'dins Phenls ,far-e. them recovered i from `the salts by I tifeating ,the same with'y :dilute v fand gthe like in onder `to .form 'the socorre- .spondne i phenols or ,naphthenic gacids.4 1 Operations time' also been .proposed by-whichfthese f, ff-valiiableconstituents fare removed and necovered f r: @f-mm Vfeed Oilsgjcntaining@ the? same @utilizingi a @sorbent such I kals fvaxfious f fofjalummumazndbwuXLte. 1

Ifihave now discovered en improved-method@ stituentsf fr from `feed oils containing thefsavme in cured and j which `oflso results thefprodnotion of `atreated oil product lofhigh quality.ll In ao- ".cordance. with my inventionthe ./mineialgoil containing the recoverable .phenolic typecomponnds fand `napolithenic ecidsds contacted Wthia;, solid meent ,Consisting Substantially fof highly n0- fi'o`ussilcaggel.; peparedffundexg certaliri specilc conditions' .whereby` jal n, critical I.`,gufintity of hyjlldmtdiwaten is 'fpeselitlnthe silica, gel Vunder /conditionsfto lfully1eni ve `these cons'titi'.ients,[fr'on the oil; The, spent "fiel 1S'thenwhtdledlioemmwtojewo Segrethe 1 totvrerbve recoves Apetroleum oil-.phenols as: lwelles petroleum oil rzeolits" oxides emcient'mannerby. which a high'yield is seging', modifizttions-z/o-Kf.` the same'. n o i Y jEigurevl illustrates a. modication of tgheg-inr-j vention irl-.WhichtheqfeedI oil islfpassed? through l A@aybed of `sili'cawgel, whileyligurea? lillusii'otes` ygin-1 *,Which ,a4` slurryl of silice ess of myV invention :may bev `readily 4,undeljstood by referencey tothe attached drawings other modification Y. `iin gel is utilized.Y y

Referi'nggpartioularl-yftogFigureyl; it ,is as I sinnedthat the"phenolctype cons ,tituent-` and` l 'naphthenioocid containing-feed Voiliis ay.petro.. 1 leum oilfj'boilng-inV the ke-io'senebil boiling range. j For 1 purposes. of i illustration it` `also, 1.asslflnlied thnththe silica gel isin bedsfandthatgtwo silica.

,gelcontactinganimatie-'employed y1I@ is,tof,be i understood that any number of units 'maybeuti-f lized and maybe arranged.irlmy` desirable inanrienv 'lhe feedoil isintrodueed intol initialvooncompletely remove vthe -phenols Iand naphthenic Phnols' ,111:11I

A`initially fkf'zzgritetztedwith wielatyely *1o/Wy boiling petifoleum oil distillate solventha'ving a prefei'e'ri- I tialfsolubilty infor. the petroleuni voil reinainingfin o o the silica.` tgelbecle This petroleum oil Washing solvent `maybeffirit1joduced iby'gmeansuj of line glik and Withdrawn by ineansfof'gline [1. :.Thejs'ilica gel :bed is thenontacted Withasolventhaviig;

a preferential selettivity'r. thefphegnmdtyple compounds Aivhzl'iofory'tliepi'poses of description lis takentobe water. "The Wateris 'introducedd l(into:invtixpl"contacting plantl by means of lliney Y illustratg Nteriol Iiows4 upwardly through zone Land eontaets'- s a, bedof silica gel which preferably iCornprisesy a. Y smallfpgrticle size svovthat a large lsurfaceglarea is secured. Temperature .andjpressure condi-1 tions are .adjusted in .a manner. to/substantiallyv 9 and withdrawn by means of line 8. Suiicient water is introduced at a temperature and pressure which is adapted to substantially fully remove the phenols from the spent silica gel bed. The silica gel bed, free of petroleum oil and aclsorbed petroleum phenols, is then contacted with a solvent having a preferential selectivity for the naphthenic acid compounds.

For the purposes of illustration, this solvent is taken to be a sulfuric acid solution which is introduced by means of line I I and withdrawn by means of line I0. The silica gel bed is then treated in a manner to fully regenerate the same. This is preferably accomplished by washing the bed with a solvent, preferably comprising Water, in order to remove the acidic constituents. The solvent for removing the acidic constituents is introduced by means of line -I2 and-Withdrawn by means of line I3. The silica gel bed, free of v acidic constituents, is heated to a temperature preferably in the range from about 400 F'. to about 750 F., in order to fully regenerate the same.` At the end of the cycle in which, the efficiency of the silica gel in contacting unit 2 drops to a certain predetermined point, the feed oil is again passed into the regenerated silica'gel in unit I. The silica gel-contacted oil is vwithv drawn from contacting unit 2 'by meanscf line I6,` withdrawn from the system, and-handled as desired. The silica gel in contacting unit 2 containing the adsorbed phenols and naphthenic acids, is handled in a manner similar to that describedy with respect tounitv I in a mannerto remove and segregate the phenols and naphvthenic acids and` to regenerate the silica gel. This is accomplished by initially washing the bed with a relatively low boiling petroleum solvent introduced by means of line I1 and Withdrawn by means of line I8, removing ythe phenolic type constituents by contacting the silica gel with a preferential solvent for the phenolic type compounds which is introduced by means of line and withdrawn by means of line I9. This solvent preferably comprises water. The naphthenic compounds are removed by contacting vthe silica gel bed with a dilute-,acid solution by heating toa temperature in -the range from about 400 F. to about 750 F. The aqueous soj- Vlution of phenols which is' removed from the respective contacting units by means Ofiline 4B is introduced into phenol recovery unit 21. In

this unit, when treating ,relatively high boiling petroleum oils th'ejrelatively. high boiling phenols will separate fromthe aqueous layer The phenol layer is withdrawn from the phenol recovery unit 21 by. means of line 28, while the aqueous layer is withdrawn by means of line 29 and preferably1 recycled as described if a phenolic solvent tofthe system.j As the petroleum oil contacted is arelatively wide 4boiling fraction and contains relatively low boiling. and relativelyvhigh boiling petroleum phenols, it may be desirable to fully recover the relatively lowboiling phenols from the aqueous' layer by distilling the same prior to returning the aqueous layer as solvent to the silica gel contacting units. This is accomplished bypassing the yaqueous layer 'to still 30, 'operated under conditions to remove overhead the aqueous layer by means of line 3l, and to remove as the bottoms the relatively low boiling phenolic constituents by means of line 32.

The acid solvent containing the naphthenic constituents, removed from the respective contacting plants by means of lines I0 and 2|, respectively, is similarly handled in a manner to segregate the naphtheniclacids. The acid solvent is introduced into naphthenic acid recovery zone 33 in which a layer separation will occur between the acid solution and the naphthenic acids. The naphthenic acids are removed by means of line 34 and further refined as desired, while the acid vlayer is withdrawn by means of line 35 and preferably recycled as acid solvent to the contacting plants as described.

- Referring specifically to Figure 2, feed oil is introduced into the system by means of line 50. The feed oil is mixed with a quantity of silica gel which for purposes of illustration is taken to be powdered silica gel and which is introduced from silica gel bin 5I byf means of screw conveyor 52.` The oiland the silica gel `are passed through'mixer 53 and then passed as a slurry by means of line 54 into agitation zone 55 which may comprise any suitable number of agitating units arranged in any desirable manner. Complete mixingisisecured by means `of agitator 56. 'Ihe mixture is withdrawn from zone 55 by means of line 51and introduced into'settling unit 58. The separation of the solid phase from the liquid phase may be facilitated by any desirable means such as baiilesysettling means, and the like. The

treated oil is withdrawn from unit 58 by means of line SS'andhandled inany desirable manner. The silica gel containing adsorbed thereonthe phenolictype compounds and naphthenic acids is withdrawn' from unit 5B `by means of line 60 `and handled Tin a manner t0' remove and recover the phenols and naphthenic acids and to substantially fully regenerate the silica gel. This is y'preferably accomplished by passing the silica gel to washing unit 5I in which the occluded relatively high boilingpetroleum oil constituents `are removed by Washing with a relatively low boiling petroleum oil solvent which is introduced by means of line 62 and withdrawn by means of line 63. The washed silica gel is introduced into phenol recovery unit 64 by means of line 65, in which the phenols are removed by contacting thesilica gel with a solvent having a preferential solubility for phenolic type compounds. Forthe purposes of illustration it is assumed that the solvent comprises Water which is introduced by means Vof -line 66' and withdrawn by means of line 61.v Ihe silica gel is passed to naphthenic acid recovery unit B8 by means of line 69 in which Vthe naphthenic acids arel removed from the silica gel by contacting with a suitable solvent which for the purposes of description is assumed to be a dilute acid solution which is introduced by v means of line 10 and withdrawn by means of fully regenerate the same.

line 1 I. The silica gel, free of adsorbed phenolic `typecomp'ounds and naphthenic acid type constituents,A is handled `in a manner to substantially 'Ihis is preferably secured by passing the silica gel to solvent con- Vtat-:ting'stage 12 by means of line 13 and treating the same with a solvent which preferably com,- prises water which is introduced bywmeans of line 'I4 and withdrawn by means of line 15.' The silica gel, free of acidicy constituents, is passed to heating unit 16 by means of line 11 and therein heated toa temperature in the general range eenen" .T13

{from-ebene 4oo-zte1ebeut m -emmey @einer re1atiye1y'smau pertieieeme;

fgel'iswithdrawn:fromfthelatterfstageivy 'mns mticularlyipowdered .silieaageL 'I'hewrnethods f oflineand recycled-'tothe @seeming-AWM. `0I.1:conta(stingfmayedae either by futilizing ifbedslor l AThe `.aqueoussolution :or phenol, wlthdrdwn'flmm by employing afslurry.

rimlt'illl'ibyTIIeenSAof linelt-'Lds 'Bhezoperating c onditionsllkewisesmayfb widee n recovery `unitlllin. which' fa. 'layermsepantlon ly maiiedgf The ilowzofjthe respectivel treating .occnrs'betweenzthe:relatlvelydiighhoetlinggpheubls agents may be either upflow or doymilow..V `fIem; A A )and Sithe Jaqueous' solution. .'Ilhe Thigh :pei-.atiues-landwpressures mayl vary and `vvll l .Ide-

-boilinglphenol's are withdrawnbymemsvnt filing lpon' the particular fed 'oil beingytreatei n while the aqueous isolutionwis withdrawn by T11) quantityand character .of'z'the ;pheno1s fand:

rmeansmflineImnd .Tecnici-dictum; .1 nistphthenic.acidspresent;v as @Well asf`uponr the` `phenolic l'ayeris withdrawn bymeansifotfmneiill particular 'fsilieevgelv .beingused andruponi-the e velistillerl.or iurther rened 1in anymermemdedrnlreed'nates'eand pertielezsize.` in general'itiszpre; n' l tble. L Underl mitteln .condltmns;. 'when :fthe iferflzedf to .employ atmospheric temperatures@ leumioil treated ais of .a'frelatiuely Midmhum 15'meswneealthoughftemxerturs in thelrage range and the aqueous` solution containgfgxdpil'om'bautiBO'PlEitozabout 250 5F'. maiyxbe'errie itivelylewboilingeolnble phenolagltzmawbelemluyiedinparticlarlinstanfees. If'the'petro1enmv- S-table teyxlistill imuenusoluhinn Nimm miiebeofmremtiyelyhighviscosity, itfmey:f.be;de` f deeeelheir ehereererieees; have Metairie he :from: recovery omit 'lf-.in:-oxder @immane :the sirable to employ heating-means forato dilute the `rebatir/ely'flcfwyboiling fnhenolsspgics-co '.20 oil y-vilitlmin inertdilution solvent, asiforlexaniple .i :5511 mueous-lsolution vte ilixltlgfilg: ixelatiuely-g lowfrboilingnpetroleum-"oillor-:witha f Ytime.:ponteinm; the withdrawn irelatiyely lownboiling ghydroearbone constituent.

yunit 8 vhyfgligsle 'FM fis ite The' feed rates mayy varymnsiderab1y:';depend fnephthenieaeidfreqevery unitzlsinmcmnrlener ing uponthe genrellprftng Conditions., the @Renatico-.cur be wrlleeifrailolle. lfhe'diliitemcdienlutlonfi wh- .meetic sevenovolumesvoti-oil;perfvolumeor silica.

Bfvoltmies lof oil fperrvolume yoifsilice'gelper hour;A

.The DIQQSgS ajmuIMethe.mountotslurry :widely veriedbV .Althoughk the ,method iq emcerably-einmhe. range'kfrom .-oneavolume' or,

employed for the recovery 'eggifqgatinwpf lailica'kgel aber 5 to lfvolurnes .geteilt phenolic; `time coustit uente navhthenief-aeids$5 eeltleougiriitfis .notlessentairit isepreferrfed that .tivelylfhis-liyhlllnsbref embed; ith za elventfwhich willyr-,removeffoclf} .'.eum ,oheriolisffen'f .,lieiroleugl. Vinaphthexue eluded .mon-tions. :from .fthe .silica-eel prior, .to immfpetroleum roils'trolling v11,1 Ythi? fmting Silica .gel'rto-'rremoye the :adsorbed y, o t

lubrinatineoil mentener. .re

the forca-nh venton. n .mprises-eevmheticmaf critical quantity olfliydrmerll .-.Inl gengporatuzres Astridi pressure general Lange ofabQut-.ltohalotl 7%',pref1- g sllletityfofrphenolspresent. Injgenerel itis Vmeeisooiumsilicate.eeiiineea mineral ter'etnqrmeltempratures andpressuresiforthe "acid, preferably withalinuteesulim .acideolu :d1laementof'the-Phenolictypeeonstituents "with a solventi'chavraterze'dbyhavingtheility XJoe -eleeirfable-i to :employoheeted ,-Weterelor-eteam f Lconstitiients. I vin rderto remove the phenolsgaltliough .injjgeni zeralthisniethodis ..not,preferred.Theraqueous acidfgtrea'ted Silica. .Y peratur'e the. general r fil ge' .rromiabeuraoov rr.

two .phases comprising a phenol ase l y l silica gel 15h31,@ attheseltempmtures #1.111 .dely 195Vboiling,solublephenolc .type 'compounds pend togsome extent .lipongthe character ofthe lpreserinvit'dsepneferred `to.recirculate:thesanieas silicagel, the particularacid"used,rand thecona phenol solvent directly totheTs'ilicalgel`cV l Y 'centration of the same.r In generalthe time isV tactingzunits.

sufciently long` to'ysecure the'f'desired porosity 70 The acid solution employed forthek removaly and the desired dehydration of the silica gel. In of the ,naphthe'nic type constituents from the general this time will vary in the general range silicagel likewise rmay Vary. COSdeIablY- Any [from labout thirty minutes to about ninety min- `mineral .acidfmay be employed, althoughfingen utes. Although a relatively large particle size eral fit'is` preferred to utilize adilute'sulfuricacid fmay be employed, in general it is preferred to' 75 having an acid concentration in the range fromr about 2% to about 10%'. "A particularly desirable solvent for/removing naphthenic type constituents from the vsilica gel comprises `a 5% sulfuric acid solution. This solution, after'the removal of the naphthenic acid constituents, is likewise preferably recycled to the system as de-A scribed.

The spent silica gel, free of naphthenic acid and phenolic type constituents, may be handled in any suitable manner in order to regenerate the same. Although'the spent silica gel, free of the phenols and naphthenic acid constituents, may be satisfactorily regeneratedby washing with solvents such as alcohol or a 95% ethyl alcohol solution or equivalent, it is preferred thatthe spent silica gel be regenerated by washing with a quantity of Water, followed by heating the same in a manner to secure they desired porosity Vand the Vdesired removal of water.

' In .order to further illustrate the present invention, the following example is given/Which should not be construed as .limiting the same in any manner whatsoever.

Example 1 A petroleum distillate boiling in the kerosene boiling range, having a phenol number'.1 of .200, was contacted with a silica gel. The silica gel Was prepared by treating an` aqueous' sodium silicate solution with a dilute sulfuric acid solution. The resulting silica gel was Washedfwith water to remove' the acidic constituents, land heated at a temperaturer of about 572 F; for -approximately thirty minutes. The silica gel had a mesh of about twenty'to sixty. When contacting the feed oil with the silica gel `at atemperature of about 70 F.' andv at a feed rate of one volume of feed oil per volume of silica gel per hour, approximately four volumes of phenol-free `feed oil were obtained per volume of silica gel.

4lhenols and-- naphthentic acid constituents were segregated and removed by initially washing the silica gel with water, then with sulfuric acid in the manner described, followed by fully regenerating the silica gel.

Apparently the silica gel of the presentinvention reacts with the naturally occurring acidic oxygen containing compounds to form reaction products which may be readily regenerated from` the silica gel. The regeneration operation may be controlled in a manner to preferentiallyrst regenerate the phenolic type constituents which may be separated. After separation of the phenolictype constituents the naphthenic acid constituents may bethen readily regenerated and separated. l

What I claim as vnew and wish to protect by Letters Patent is:

1. Process for the recovery and segregation of naturally occurring petroleum oilphenols and petroleum oil naphthenic acids from petroleum oils which comprises contacting feed petroleum oil containing these materials with a solid reagent consisting substantially of a highly porous 1 A 200 phenol number is equivalent to 0.2% of phenols, expressed as equivalent milligrams of tertiary amyl phenol per 100 milliliters of oil.

syntheticsilica gel containing from about 1% to :about 7% of water, at atmospheric temperatures and-pressuresy whereby these materials are removed fromfthe oil, separating the silica gel from the oil, contacting the silica. gel at atmospheric temperatures and pressures with water `whereby the petroleum voil phenols are recovered from the silica gel, contacting the silica gel free of petroleumfoil phenols withA a dilute acid solution at'atmospheric temperatures and pressures consisting essentially 'of a highly porous synthetic silica gel containing from about 1% to about 7% `of water, which is prepared by acidifying a sodium silicate solution Withra sulfuric acid solution of a Vconcentration*in the rangev from about 5% to "about 20'% 'followed by washing with water and heating at a 'temperature in the range from about .550 F.'t about'600 F., at atmospheric temperatures I and pressures, whereby these compounds are removed from the oil, separating the silica gel,

recovering `the naturally occurring acidic oxygen containing ycompounds from said silica gel, and

regenerating 'the same.

f V3.;tPro'c'ess for the recovery'and )segregation of various* naturally occurring acidic oxygen con- 'tainingjcompounds from petroleum oils which comprises" contacting a feed petroleum oil containing fthese compounds' with a solid Vreagent vccinsistin'g'essentially ofa highly porous synthetic "'silica gel containing from about 1% to about 7% o f water, which 'is prepared by acidifying a sodium silicate solution with a mineral acid followed by washing the acid treated sodium silicate with a'lsolvrent and heating to a temperature in the range l,from about 400 F. to about 750 F., at atmospherictemperatures and pressures, whereby these compounds are removed from the oil, separating the silica gel, recovering the naturally occurring acidic oxygen containing compounds from saidsilica gel and regenerating the same.

' 4."Process forthe recovery and segregation of variousunaturally occurring acidic oxygen containing compounds from petroleum oils, which ycomprises'contacting feed petroleum oils containing these compounds with a solid reagent consisting substantially of a highly porous synrthetic silica gel containing from about 1% to containing compounds from said silica gel by initially treating the silica gel with Water and then treating the silica gel with a dilute acid solution, and regenerating the silica gel.

BARNEY R. STRICKLAND. 

